In Thunderbird:
1. Click on "Tools" and then "Account Settings".
2. Click on "Junk Settings" on the left.
3. Check "Do not mark mail as junk if the sender is in:" and select "Personal Address Book" in the drop down menu beside it. Press "OK" at the bottom.
4. Click on "Tools" and then "Address Book".
5. Click on "New Card".
6. Type "Chief Architect" in the Name area and "" in E-mail.
7. Click "OK".